It is quite normal to feel shock, anger and grief (and maybe other things) in a situation like this. Your world has turned upside down.
It is also common for people to think that when their loved one stops drinking , everything will be great.
The challenge as mentioned above is that when someone who is addicted to alcohol stops drinking, the work is just beginning.
Staying sober is very tricky and rehab is one way people learn the skills to avoid falling back into the pattern. It is a lot of work and takes time and energy. Drugs and alcohol are one way people sometimes cope with emotional issues and the stress of life, and a lot of the rehab work is looking at that and building new skills. That alone will change your relationship.
There is also the physical recovery and skills to avoid triggers. So in a way, expecting your boyfriend to be available to you now is like expecting that of someone who has just been diagnosed with cancer. Their attention is necessarily shifted.
FeelingGreat gives good advice - learn what you can about recovery so you know what is going on. He will need to focus on his recovery and simply may not have the bandwidth to provide you the love and affection you want right now.
To focus on creating a satisfying life for yourself and allow events to unfold you will be strengthening yourself and giving him space to do the same.
If you can do that and if your relationship survives this, you'll both be in a stronger place to have a satisfying relationship.
Prayers for your growth and happiness.